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Two new polymorphs of 4-(
N,
N-dimethylamino)benzoic acid, C
9H
11NO
2, resulting from the attempted cocrystallization in ethanol of 4-(
N,
N-dimethylamino)benzoic acid and a mixture of 3-(
N,
N-dimethylamino)benzoic acid and 3-(3-pyridyl)-2-pyridone producing one polymorph, and a mixture of 3-(
N,
N-dimethylamino)benzoic acid and 5-methoxy-3,3′-bipyridine producing the second polymorph, have been crystallographically characterized. The primary intermolecular O—H
O hydrogen bonds generate a dimeric acid–acid motif that is present in all three polymorphs.
Supporting information
CCDC references: 294331; 294332
Crystals of (II) and (III) were obtained by slow evaporation of 50% aqueous ethanol solutions of 4-N,N-dimethylaminobenzoic acid, 3-N,N-dimethylaminobenzoic acid and 3-(3-pyridyl)-2-pyridone (in 1:1:1 stoichiometry), and of 4-N,N-dimethylaminobenzoic acid, 3-N,N-dimethylaminobenzoic acid and 5-methoxy-3,3'-bipyridine (in 1:1:1 stoichiometry), respectively.
H atoms were assigned to idealized positions and were allowed to ride, except for the carboxylic acid H atom, whose coordinates were allowed to refine. Heavy atoms were refined with anisotropic displacement parameters. Neither data set was corrected for absorption [the linear absorption coefficients are 0.09 and 0.10 mm−1 for (II) and (III), respectively]. For (III), initial structural models included a single protonation site for the two unique carboxylic acids. Difference electron density maps, as well as the nearly identical C—O bond distances, indicated disorder of the acid H atom across the two O atoms of each acid. To accommodate this disorder, H atoms were placed on the difference peaks and the total occupancy for the two H atoms of each unique acid was constrained to 1. Distance restraints and damping were applied for the initial stages of refinement; these were both relaxed and eventually removed. For both molecules, refinement led to a nearly equal ratio of H-atom populations.
For both compounds, data collection: SMART (Bruker, 1999); cell refinement: SMART; data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.
(II) 4-(dimethylamino)benzoic acid
top
Crystal data top
C9H11NO2 | F(000) = 352 |
Mr = 165.19 | Dx = 1.320 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 10.3202 (10) Å | Cell parameters from 1626 reflections |
b = 7.4068 (8) Å | θ = 2.8–27.7° |
c = 11.2845 (11) Å | µ = 0.09 mm−1 |
β = 105.505 (5)° | T = 173 K |
V = 831.19 (15) Å3 | Plate, colorless |
Z = 4 | 0.35 × 0.30 × 0.10 mm |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1280 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.054 |
Graphite monochromator | θmax = 28.0°, θmin = 1.9° |
ϕ and ω scans | h = −13→12 |
5542 measured reflections | k = −9→9 |
1982 independent reflections | l = −14→14 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.047 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.132 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.96 | w = 1/[σ2(Fo2) + (0.080P)2] where P = (Fo2 + 2Fc2)/3 |
1982 reflections | (Δ/σ)max < 0.001 |
223 parameters | Δρmax = 0.20 e Å−3 |
1 restraint | Δρmin = −0.23 e Å−3 |
Crystal data top
C9H11NO2 | V = 831.19 (15) Å3 |
Mr = 165.19 | Z = 4 |
Monoclinic, P21 | Mo Kα radiation |
a = 10.3202 (10) Å | µ = 0.09 mm−1 |
b = 7.4068 (8) Å | T = 173 K |
c = 11.2845 (11) Å | 0.35 × 0.30 × 0.10 mm |
β = 105.505 (5)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1280 reflections with I > 2σ(I) |
5542 measured reflections | Rint = 0.054 |
1982 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.047 | 1 restraint |
wR(F2) = 0.132 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.96 | Δρmax = 0.20 e Å−3 |
1982 reflections | Δρmin = −0.23 e Å−3 |
223 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C11 | 0.2966 (3) | 0.5022 (4) | 0.0268 (3) | 0.0253 (7) | |
C12 | 0.3923 (3) | 0.4249 (4) | −0.0231 (3) | 0.0261 (7) | |
H12 | 0.3643 | 0.3676 | −0.1011 | 0.031* | |
C13 | 0.5262 (3) | 0.4293 (4) | 0.0372 (3) | 0.0279 (7) | |
H13 | 0.5896 | 0.3752 | 0.0006 | 0.034* | |
C14 | 0.5707 (3) | 0.5122 (4) | 0.1520 (3) | 0.0239 (6) | |
N14 | 0.7052 (2) | 0.5170 (4) | 0.2123 (2) | 0.0312 (6) | |
C18 | 0.8051 (3) | 0.4624 (5) | 0.1514 (3) | 0.0428 (10) | |
H18A | 0.8939 | 0.4614 | 0.2109 | 0.064* | |
H18B | 0.8056 | 0.5477 | 0.0851 | 0.064* | |
H18C | 0.7839 | 0.3412 | 0.1169 | 0.064* | |
C19 | 0.7511 (3) | 0.6152 (5) | 0.3256 (3) | 0.0392 (9) | |
H19A | 0.8431 | 0.5783 | 0.3674 | 0.059* | |
H19B | 0.6920 | 0.5895 | 0.3786 | 0.059* | |
H19C | 0.7494 | 0.7449 | 0.3082 | 0.059* | |
C15 | 0.4749 (3) | 0.5900 (4) | 0.2034 (3) | 0.0284 (7) | |
H15 | 0.5024 | 0.6474 | 0.2814 | 0.034* | |
C16 | 0.3407 (3) | 0.5836 (4) | 0.1410 (3) | 0.0268 (7) | |
H16 | 0.2766 | 0.6363 | 0.1772 | 0.032* | |
C17 | 0.1552 (3) | 0.4974 (5) | −0.0418 (3) | 0.0296 (7) | |
O17 | 0.0727 (2) | 0.5754 (4) | 0.0117 (2) | 0.0415 (7) | |
H17 | −0.009 (4) | 0.572 (6) | −0.036 (3) | 0.050* | |
O18 | 0.1170 (2) | 0.4278 (4) | −0.1451 (2) | 0.0387 (6) | |
C21 | 0.6483 (3) | 0.5130 (5) | 0.6993 (3) | 0.0256 (7) | |
C22 | 0.5555 (3) | 0.6052 (4) | 0.7452 (3) | 0.0285 (7) | |
H22 | 0.5850 | 0.6677 | 0.8212 | 0.034* | |
C23 | 0.4214 (3) | 0.6080 (4) | 0.6829 (3) | 0.0278 (7) | |
H23 | 0.3601 | 0.6732 | 0.7163 | 0.033* | |
C24 | 0.3731 (3) | 0.5164 (4) | 0.5708 (3) | 0.0271 (7) | |
N24 | 0.2399 (2) | 0.5198 (4) | 0.5099 (2) | 0.0352 (7) | |
C28 | 0.1441 (4) | 0.6098 (6) | 0.5613 (4) | 0.0482 (10) | |
H28A | 0.0532 | 0.5897 | 0.5083 | 0.072* | |
H28B | 0.1633 | 0.7396 | 0.5671 | 0.072* | |
H28C | 0.1506 | 0.5615 | 0.6435 | 0.072* | |
C29 | 0.1884 (4) | 0.4253 (6) | 0.3957 (3) | 0.0463 (10) | |
H29A | 0.0954 | 0.4629 | 0.3582 | 0.069* | |
H29B | 0.1910 | 0.2950 | 0.4112 | 0.069* | |
H29C | 0.2438 | 0.4536 | 0.3398 | 0.069* | |
C25 | 0.4678 (3) | 0.4233 (5) | 0.5255 (3) | 0.0275 (7) | |
H25 | 0.4387 | 0.3599 | 0.4499 | 0.033* | |
C26 | 0.6013 (3) | 0.4215 (4) | 0.5876 (3) | 0.0269 (7) | |
H26 | 0.6630 | 0.3571 | 0.5543 | 0.032* | |
C27 | 0.7889 (3) | 0.5108 (5) | 0.7685 (3) | 0.0274 (7) | |
O27 | 0.8695 (2) | 0.4166 (4) | 0.7200 (2) | 0.0395 (6) | |
H27 | 0.950 (4) | 0.419 (6) | 0.759 (3) | 0.047* | |
O28 | 0.8294 (2) | 0.5906 (4) | 0.8664 (2) | 0.0402 (6) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C11 | 0.0280 (15) | 0.0232 (14) | 0.0247 (16) | −0.0003 (15) | 0.0071 (12) | 0.0009 (16) |
C12 | 0.0313 (17) | 0.0245 (15) | 0.0205 (16) | −0.0019 (14) | 0.0036 (13) | −0.0009 (15) |
C13 | 0.0327 (17) | 0.0235 (15) | 0.0289 (18) | 0.0065 (14) | 0.0106 (14) | 0.0027 (16) |
C14 | 0.0257 (15) | 0.0205 (13) | 0.0256 (16) | −0.0005 (15) | 0.0073 (13) | 0.0025 (15) |
N14 | 0.0292 (14) | 0.0321 (14) | 0.0298 (15) | 0.0026 (14) | 0.0038 (11) | −0.0018 (15) |
C18 | 0.0353 (19) | 0.052 (2) | 0.039 (2) | 0.0039 (16) | 0.0078 (16) | −0.0084 (18) |
C19 | 0.0310 (18) | 0.048 (2) | 0.034 (2) | 0.0049 (16) | 0.0000 (15) | −0.0029 (18) |
C15 | 0.0361 (18) | 0.0279 (16) | 0.0216 (17) | −0.0005 (15) | 0.0086 (14) | −0.0037 (16) |
C16 | 0.0280 (16) | 0.0284 (15) | 0.0265 (17) | −0.0003 (14) | 0.0115 (13) | −0.0021 (16) |
C17 | 0.0314 (16) | 0.0304 (16) | 0.0290 (18) | −0.0023 (15) | 0.0112 (14) | −0.0024 (16) |
O17 | 0.0271 (12) | 0.0585 (16) | 0.0386 (15) | 0.0032 (12) | 0.0084 (11) | −0.0106 (13) |
O18 | 0.0315 (13) | 0.0491 (14) | 0.0344 (14) | 0.0015 (11) | 0.0069 (11) | −0.0107 (12) |
C21 | 0.0274 (15) | 0.0252 (15) | 0.0246 (16) | −0.0009 (16) | 0.0079 (13) | 0.0044 (17) |
C22 | 0.0363 (19) | 0.0264 (17) | 0.0244 (18) | 0.0007 (15) | 0.0108 (15) | −0.0018 (15) |
C23 | 0.0301 (17) | 0.0278 (17) | 0.0269 (18) | 0.0009 (14) | 0.0099 (14) | −0.0008 (16) |
C24 | 0.0304 (17) | 0.0241 (15) | 0.0255 (17) | −0.0032 (17) | 0.0052 (14) | 0.0038 (17) |
N24 | 0.0293 (14) | 0.0442 (17) | 0.0297 (16) | 0.0025 (15) | 0.0035 (12) | −0.0045 (16) |
C28 | 0.0319 (18) | 0.059 (3) | 0.049 (2) | 0.0035 (18) | 0.0036 (17) | −0.007 (2) |
C29 | 0.0352 (19) | 0.061 (2) | 0.040 (2) | −0.006 (2) | 0.0053 (17) | −0.015 (2) |
C25 | 0.0315 (17) | 0.0287 (16) | 0.0217 (17) | −0.0038 (15) | 0.0060 (13) | −0.0002 (16) |
C26 | 0.0296 (17) | 0.0287 (16) | 0.0231 (17) | 0.0006 (15) | 0.0083 (14) | −0.0018 (17) |
C27 | 0.0312 (16) | 0.0237 (14) | 0.0275 (18) | −0.0003 (15) | 0.0084 (14) | −0.0008 (16) |
O27 | 0.0279 (12) | 0.0499 (14) | 0.0388 (15) | 0.0055 (12) | 0.0057 (11) | −0.0122 (13) |
O28 | 0.0308 (13) | 0.0504 (15) | 0.0355 (15) | 0.0069 (12) | 0.0022 (11) | −0.0102 (13) |
Geometric parameters (Å, º) top
C11—C16 | 1.384 (4) | C21—C22 | 1.385 (4) |
C11—C12 | 1.385 (4) | C21—C26 | 1.399 (4) |
C11—C17 | 1.459 (4) | C21—C27 | 1.453 (4) |
C12—C13 | 1.368 (4) | C22—C23 | 1.375 (5) |
C12—H12 | 0.9500 | C22—H22 | 0.9500 |
C13—C14 | 1.395 (4) | C23—C24 | 1.404 (4) |
C13—H13 | 0.9500 | C23—H23 | 0.9500 |
C14—N14 | 1.373 (4) | C24—N24 | 1.363 (4) |
C14—C15 | 1.397 (4) | C24—C25 | 1.400 (4) |
N14—C19 | 1.438 (4) | N24—C28 | 1.437 (4) |
N14—C18 | 1.442 (4) | N24—C29 | 1.437 (4) |
C18—H18A | 0.9800 | C28—H28A | 0.9800 |
C18—H18B | 0.9800 | C28—H28B | 0.9800 |
C18—H18C | 0.9800 | C28—H28C | 0.9800 |
C19—H19A | 0.9800 | C29—H29A | 0.9800 |
C19—H19B | 0.9800 | C29—H29B | 0.9800 |
C19—H19C | 0.9800 | C29—H29C | 0.9800 |
C15—C16 | 1.377 (4) | C25—C26 | 1.368 (4) |
C15—H15 | 0.9500 | C25—H25 | 0.9500 |
C16—H16 | 0.9500 | C26—H26 | 0.9500 |
C17—O18 | 1.238 (4) | C27—O28 | 1.224 (4) |
C17—O17 | 1.303 (4) | C27—O27 | 1.312 (4) |
O17—H17 | 0.87 (4) | O27—H27 | 0.83 (4) |
| | | |
C16—C11—C12 | 117.8 (3) | C22—C21—C26 | 117.9 (3) |
C16—C11—C17 | 122.5 (3) | C22—C21—C27 | 119.7 (3) |
C12—C11—C17 | 119.7 (3) | C26—C21—C27 | 122.3 (3) |
C13—C12—C11 | 121.5 (3) | C23—C22—C21 | 121.2 (3) |
C13—C12—H12 | 119.2 | C23—C22—H22 | 119.4 |
C11—C12—H12 | 119.2 | C21—C22—H22 | 119.4 |
C12—C13—C14 | 120.7 (3) | C22—C23—C24 | 121.3 (3) |
C12—C13—H13 | 119.7 | C22—C23—H23 | 119.4 |
C14—C13—H13 | 119.7 | C24—C23—H23 | 119.4 |
N14—C14—C13 | 120.6 (3) | N24—C24—C25 | 122.2 (3) |
N14—C14—C15 | 121.1 (3) | N24—C24—C23 | 120.8 (3) |
C13—C14—C15 | 118.2 (3) | C25—C24—C23 | 117.0 (3) |
C14—N14—C19 | 120.2 (3) | C24—N24—C28 | 121.0 (3) |
C14—N14—C18 | 120.9 (3) | C24—N24—C29 | 121.7 (3) |
C19—N14—C18 | 117.3 (3) | C28—N24—C29 | 117.3 (3) |
N14—C18—H18A | 109.5 | N24—C28—H28A | 109.5 |
N14—C18—H18B | 109.5 | N24—C28—H28B | 109.5 |
H18A—C18—H18B | 109.5 | H28A—C28—H28B | 109.5 |
N14—C18—H18C | 109.5 | N24—C28—H28C | 109.5 |
H18A—C18—H18C | 109.5 | H28A—C28—H28C | 109.5 |
H18B—C18—H18C | 109.5 | H28B—C28—H28C | 109.5 |
N14—C19—H19A | 109.5 | N24—C29—H29A | 109.5 |
N14—C19—H19B | 109.5 | N24—C29—H29B | 109.5 |
H19A—C19—H19B | 109.5 | H29A—C29—H29B | 109.5 |
N14—C19—H19C | 109.5 | N24—C29—H29C | 109.5 |
H19A—C19—H19C | 109.5 | H29A—C29—H29C | 109.5 |
H19B—C19—H19C | 109.5 | H29B—C29—H29C | 109.5 |
C16—C15—C14 | 120.0 (3) | C26—C25—C24 | 121.6 (3) |
C16—C15—H15 | 120.0 | C26—C25—H25 | 119.2 |
C14—C15—H15 | 120.0 | C24—C25—H25 | 119.2 |
C15—C16—C11 | 121.7 (3) | C25—C26—C21 | 121.0 (3) |
C15—C16—H16 | 119.1 | C25—C26—H26 | 119.5 |
C11—C16—H16 | 119.1 | C21—C26—H26 | 119.5 |
O18—C17—O17 | 122.5 (3) | O28—C27—O27 | 122.2 (3) |
O18—C17—C11 | 122.1 (3) | O28—C27—C21 | 122.0 (3) |
O17—C17—C11 | 115.3 (3) | O27—C27—C21 | 115.8 (3) |
C17—O17—H17 | 110 (3) | C27—O27—H27 | 115 (3) |
| | | |
C16—C11—C12—C13 | −0.5 (5) | C26—C21—C22—C23 | −0.4 (5) |
C17—C11—C12—C13 | 178.9 (3) | C27—C21—C22—C23 | −179.1 (3) |
C11—C12—C13—C14 | 0.1 (5) | C21—C22—C23—C24 | 0.5 (5) |
C12—C13—C14—N14 | −179.8 (3) | C22—C23—C24—N24 | 179.9 (3) |
C12—C13—C14—C15 | 0.2 (5) | C22—C23—C24—C25 | −0.3 (5) |
C13—C14—N14—C19 | 175.0 (3) | C25—C24—N24—C28 | 177.2 (4) |
C15—C14—N14—C19 | −5.0 (5) | C23—C24—N24—C28 | −3.0 (5) |
C13—C14—N14—C18 | 9.8 (5) | C25—C24—N24—C29 | 0.9 (5) |
C15—C14—N14—C18 | −170.2 (3) | C23—C24—N24—C29 | −179.4 (3) |
N14—C14—C15—C16 | 180.0 (3) | N24—C24—C25—C26 | 179.8 (3) |
C13—C14—C15—C16 | 0.0 (5) | C23—C24—C25—C26 | 0.1 (5) |
C14—C15—C16—C11 | −0.4 (5) | C24—C25—C26—C21 | 0.0 (5) |
C12—C11—C16—C15 | 0.6 (5) | C22—C21—C26—C25 | 0.1 (5) |
C17—C11—C16—C15 | −178.7 (3) | C27—C21—C26—C25 | 178.8 (3) |
C16—C11—C17—O18 | 178.4 (3) | C22—C21—C27—O28 | −1.1 (5) |
C12—C11—C17—O18 | −0.9 (5) | C26—C21—C27—O28 | −179.8 (3) |
C16—C11—C17—O17 | 0.1 (5) | C22—C21—C27—O27 | 178.3 (3) |
C12—C11—C17—O17 | −179.2 (3) | C26—C21—C27—O27 | −0.3 (5) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O17—H17···O28i | 0.87 (4) | 1.74 (4) | 2.609 (3) | 174 (4) |
O27—H27···O18ii | 0.83 (4) | 1.78 (4) | 2.602 (3) | 175 (4) |
Symmetry codes: (i) x−1, y, z−1; (ii) x+1, y, z+1. |
(III) 4-(dimethylamino)benzoic acid
top
Crystal data top
C9H11NO2 | Z = 4 |
Mr = 165.19 | F(000) = 352 |
Triclinic, P1 | Dx = 1.337 Mg m−3 |
a = 9.6507 (11) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.8918 (11) Å | Cell parameters from 1288 reflections |
c = 10.0082 (10) Å | θ = 2.2–26.8° |
α = 76.118 (6)° | µ = 0.10 mm−1 |
β = 67.655 (7)° | T = 173 K |
γ = 69.334 (9)° | Plate, colorless |
V = 820.61 (15) Å3 | 0.30 × 0.20 × 0.10 mm |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1717 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.059 |
Graphite monochromator | θmax = 27.5°, θmin = 2.2° |
ϕ and ω scans | h = −11→12 |
5655 measured reflections | k = −12→12 |
3506 independent reflections | l = −12→12 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.85 | w = 1/[σ2(Fo2) + (0.07P)2] where P = (Fo2 + 2Fc2)/3 |
3506 reflections | (Δ/σ)max < 0.001 |
235 parameters | Δρmax = 0.21 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
Crystal data top
C9H11NO2 | γ = 69.334 (9)° |
Mr = 165.19 | V = 820.61 (15) Å3 |
Triclinic, P1 | Z = 4 |
a = 9.6507 (11) Å | Mo Kα radiation |
b = 9.8918 (11) Å | µ = 0.10 mm−1 |
c = 10.0082 (10) Å | T = 173 K |
α = 76.118 (6)° | 0.30 × 0.20 × 0.10 mm |
β = 67.655 (7)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1717 reflections with I > 2σ(I) |
5655 measured reflections | Rint = 0.059 |
3506 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.85 | Δρmax = 0.21 e Å−3 |
3506 reflections | Δρmin = −0.28 e Å−3 |
235 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. X-ray data were collected on a Bruker SMART 1000 four-circle CCD diffractometer using a fine-focus molybdenum Ka tube. Data were collected using SMART (1997). Initial cell constants were found by small widely separated "matrix" runs. Preliminary Laué symmetry was determined from axial images. For both structures, an entire hemisphere of reciprocal space was collected. Scan speed and scan width were chosen based on scattering power and peak rocking curves. Data were collected at −100 °C, using 0.25° scan width. Unit cell constants and orientation matrix were improved by least-squares refinement of reflections "thresholded" from the entire dataset. Integration was performed with SAINT (1997), using this improved unit cell as a starting point. Precise unit cell constants were calculated in SAINT from the final merged dataset. Lorenz and polarization corrections were applied. Laué symmetry, space group, and unit-cell contents were found with XPREP. Friedel opposites were merged for the noncentrosymmetric II. Data were reduced with SHELXTL (1997). The structures were solved in all cases by direct methods. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
C11 | 0.3291 (2) | 0.3217 (2) | 0.8360 (2) | 0.0278 (5) | |
C12 | 0.3661 (2) | 0.3508 (2) | 0.6857 (2) | 0.0302 (5) | |
H12 | 0.4352 | 0.2755 | 0.6274 | 0.036* | |
C13 | 0.3056 (2) | 0.4851 (2) | 0.6196 (2) | 0.0299 (5) | |
H13 | 0.3330 | 0.5017 | 0.5166 | 0.036* | |
C14 | 0.2033 (2) | 0.5985 (2) | 0.7027 (2) | 0.0280 (5) | |
N14 | 0.1411 (2) | 0.73427 (19) | 0.63953 (19) | 0.0369 (5) | |
C18 | 0.0449 (3) | 0.8517 (2) | 0.7270 (3) | 0.0463 (6) | |
H18A | 0.1030 | 0.8643 | 0.7826 | 0.069* | |
H18B | −0.0508 | 0.8285 | 0.7943 | 0.069* | |
H18C | 0.0171 | 0.9419 | 0.6635 | 0.069* | |
C19 | 0.1843 (3) | 0.7676 (2) | 0.4839 (2) | 0.0423 (6) | |
H19A | 0.1215 | 0.8660 | 0.4587 | 0.063* | |
H19B | 0.1653 | 0.6973 | 0.4437 | 0.063* | |
H19C | 0.2956 | 0.7623 | 0.4432 | 0.063* | |
C15 | 0.1645 (2) | 0.5684 (2) | 0.8542 (2) | 0.0303 (5) | |
H15 | 0.0941 | 0.6426 | 0.9134 | 0.036* | |
C16 | 0.2272 (2) | 0.4326 (2) | 0.9183 (2) | 0.0299 (5) | |
H16 | 0.1999 | 0.4147 | 1.0213 | 0.036* | |
C17 | 0.4002 (2) | 0.1799 (2) | 0.9055 (2) | 0.0317 (5) | |
O17 | 0.49830 (19) | 0.08182 (17) | 0.82613 (17) | 0.0435 (4) | |
H17 | 0.549 (5) | 0.006 (7) | 0.883 (5) | 0.052* | 0.57 (5) |
O18 | 0.36301 (19) | 0.16002 (18) | 1.04317 (17) | 0.0432 (4) | |
H18 | 0.419 (7) | 0.090 (10) | 1.080 (8) | 0.052* | 0.43 (5) |
C21 | 0.8391 (2) | 0.3220 (2) | 0.8316 (2) | 0.0276 (5) | |
C22 | 0.6787 (2) | 0.3752 (2) | 0.8573 (2) | 0.0307 (5) | |
H22A | 0.6138 | 0.3158 | 0.9174 | 0.037* | |
C23 | 0.6117 (2) | 0.5109 (2) | 0.7980 (2) | 0.0315 (5) | |
H23A | 0.5016 | 0.5438 | 0.8172 | 0.038* | |
C24 | 0.7030 (2) | 0.6022 (2) | 0.7094 (2) | 0.0281 (5) | |
N24 | 0.63636 (19) | 0.73817 (19) | 0.65204 (19) | 0.0351 (5) | |
C28 | 0.4685 (2) | 0.7994 (2) | 0.6941 (3) | 0.0441 (6) | |
H28A | 0.4424 | 0.9005 | 0.6489 | 0.066* | |
H28B | 0.4246 | 0.7966 | 0.8003 | 0.066* | |
H28C | 0.4243 | 0.7427 | 0.6619 | 0.066* | |
C29A | 0.7306 (3) | 0.8344 (2) | 0.5672 (3) | 0.0469 (6) | |
H29A | 0.6635 | 0.9275 | 0.5359 | 0.070* | |
H29B | 0.8101 | 0.7899 | 0.4815 | 0.070* | |
H29C | 0.7822 | 0.8511 | 0.6267 | 0.070* | |
C25 | 0.8649 (2) | 0.5474 (2) | 0.6821 (2) | 0.0309 (5) | |
H25A | 0.9305 | 0.6056 | 0.6205 | 0.037* | |
C26 | 0.9302 (2) | 0.4117 (2) | 0.7424 (2) | 0.0300 (5) | |
H26A | 1.0404 | 0.3780 | 0.7230 | 0.036* | |
C27 | 0.9090 (2) | 0.1808 (2) | 0.8992 (2) | 0.0310 (5) | |
O27 | 0.82245 (17) | 0.10064 (17) | 0.97916 (17) | 0.0413 (4) | |
H27 | 0.872 (6) | 0.018 (7) | 1.023 (6) | 0.050* | 0.55 (5) |
O28 | 1.05549 (17) | 0.14058 (17) | 0.87839 (19) | 0.0420 (4) | |
H28 | 1.096 (7) | 0.066 (9) | 0.927 (7) | 0.050* | 0.45 (5) |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C11 | 0.0244 (10) | 0.0293 (12) | 0.0299 (12) | −0.0092 (9) | −0.0054 (9) | −0.0078 (10) |
C12 | 0.0246 (10) | 0.0323 (12) | 0.0306 (12) | −0.0063 (9) | −0.0031 (9) | −0.0116 (10) |
C13 | 0.0284 (10) | 0.0369 (13) | 0.0244 (11) | −0.0119 (10) | −0.0045 (9) | −0.0070 (9) |
C14 | 0.0257 (10) | 0.0271 (12) | 0.0326 (12) | −0.0091 (9) | −0.0090 (9) | −0.0050 (10) |
N14 | 0.0468 (11) | 0.0314 (11) | 0.0310 (10) | −0.0069 (9) | −0.0139 (9) | −0.0062 (9) |
C18 | 0.0576 (15) | 0.0319 (13) | 0.0438 (14) | 0.0022 (11) | −0.0214 (12) | −0.0095 (11) |
C19 | 0.0419 (13) | 0.0391 (14) | 0.0383 (14) | −0.0068 (11) | −0.0130 (11) | 0.0010 (11) |
C15 | 0.0292 (11) | 0.0315 (12) | 0.0309 (12) | −0.0077 (9) | −0.0076 (9) | −0.0104 (10) |
C16 | 0.0307 (11) | 0.0340 (12) | 0.0240 (11) | −0.0106 (10) | −0.0042 (9) | −0.0077 (9) |
C17 | 0.0298 (11) | 0.0316 (13) | 0.0308 (12) | −0.0093 (10) | −0.0036 (10) | −0.0082 (10) |
O17 | 0.0473 (10) | 0.0303 (9) | 0.0385 (10) | 0.0018 (8) | −0.0077 (8) | −0.0092 (8) |
O18 | 0.0522 (10) | 0.0351 (10) | 0.0312 (10) | −0.0040 (8) | −0.0102 (8) | −0.0032 (7) |
C21 | 0.0283 (11) | 0.0304 (12) | 0.0240 (11) | −0.0087 (9) | −0.0044 (9) | −0.0096 (9) |
C22 | 0.0275 (11) | 0.0359 (13) | 0.0271 (11) | −0.0117 (10) | −0.0028 (9) | −0.0076 (10) |
C23 | 0.0275 (10) | 0.0389 (13) | 0.0275 (11) | −0.0121 (10) | −0.0064 (9) | −0.0036 (10) |
C24 | 0.0296 (11) | 0.0325 (12) | 0.0218 (11) | −0.0104 (9) | −0.0044 (9) | −0.0069 (9) |
N24 | 0.0305 (10) | 0.0345 (11) | 0.0360 (11) | −0.0099 (8) | −0.0082 (8) | −0.0004 (9) |
C28 | 0.0337 (12) | 0.0408 (14) | 0.0491 (15) | −0.0061 (11) | −0.0118 (11) | −0.0001 (12) |
C29A | 0.0443 (13) | 0.0359 (14) | 0.0510 (15) | −0.0144 (11) | −0.0099 (12) | 0.0066 (12) |
C25 | 0.0308 (11) | 0.0338 (12) | 0.0281 (12) | −0.0125 (10) | −0.0055 (9) | −0.0061 (10) |
C26 | 0.0244 (10) | 0.0326 (12) | 0.0305 (12) | −0.0089 (9) | −0.0022 (9) | −0.0099 (10) |
C27 | 0.0316 (11) | 0.0325 (13) | 0.0285 (11) | −0.0108 (10) | −0.0033 (9) | −0.0118 (10) |
O27 | 0.0389 (9) | 0.0334 (10) | 0.0418 (10) | −0.0114 (8) | −0.0050 (8) | 0.0007 (8) |
O28 | 0.0310 (9) | 0.0343 (10) | 0.0547 (11) | −0.0052 (7) | −0.0132 (8) | −0.0027 (8) |
Geometric parameters (Å, º) top
C11—C16 | 1.380 (3) | C21—C22 | 1.388 (3) |
C11—C12 | 1.389 (3) | C21—C26 | 1.390 (3) |
C11—C17 | 1.462 (3) | C21—C27 | 1.447 (3) |
C12—C13 | 1.366 (3) | C22—C23 | 1.367 (3) |
C12—H12 | 0.9500 | C22—H22A | 0.9500 |
C13—C14 | 1.402 (3) | C23—C24 | 1.401 (3) |
C13—H13 | 0.9500 | C23—H23A | 0.9500 |
C14—N14 | 1.370 (3) | C24—N24 | 1.361 (3) |
C14—C15 | 1.400 (3) | C24—C25 | 1.399 (3) |
N14—C19 | 1.437 (3) | N24—C28 | 1.442 (2) |
N14—C18 | 1.445 (2) | N24—C29A | 1.446 (2) |
C18—H18A | 0.9800 | C28—H28A | 0.9800 |
C18—H18B | 0.9800 | C28—H28B | 0.9800 |
C18—H18C | 0.9800 | C28—H28C | 0.9800 |
C19—H19A | 0.9800 | C29A—H29A | 0.9800 |
C19—H19B | 0.9800 | C29A—H29B | 0.9800 |
C19—H19C | 0.9800 | C29A—H29C | 0.9800 |
C15—C16 | 1.375 (3) | C25—C26 | 1.367 (3) |
C15—H15 | 0.9500 | C25—H25A | 0.9500 |
C16—H16 | 0.9500 | C26—H26A | 0.9500 |
C17—O18 | 1.269 (2) | C27—O28 | 1.273 (2) |
C17—O17 | 1.272 (2) | C27—O27 | 1.273 (2) |
O17—H17 | 0.93 (6) | O27—H27 | 0.89 (7) |
O18—H18 | 0.83 (9) | O28—H28 | 0.84 (9) |
| | | |
C16—C11—C12 | 118.02 (19) | C22—C21—C26 | 117.6 (2) |
C16—C11—C17 | 120.61 (18) | C22—C21—C27 | 121.51 (18) |
C12—C11—C17 | 121.32 (18) | C26—C21—C27 | 120.89 (18) |
C13—C12—C11 | 121.65 (19) | C23—C22—C21 | 121.59 (19) |
C13—C12—H12 | 119.2 | C23—C22—H22A | 119.2 |
C11—C12—H12 | 119.2 | C21—C22—H22A | 119.2 |
C12—C13—C14 | 120.54 (19) | C22—C23—C24 | 120.99 (18) |
C12—C13—H13 | 119.7 | C22—C23—H23A | 119.5 |
C14—C13—H13 | 119.7 | C24—C23—H23A | 119.5 |
N14—C14—C15 | 120.41 (19) | N24—C24—C25 | 121.68 (19) |
N14—C14—C13 | 121.88 (19) | N24—C24—C23 | 121.09 (18) |
C15—C14—C13 | 117.71 (19) | C25—C24—C23 | 117.23 (19) |
C14—N14—C19 | 120.82 (18) | C24—N24—C28 | 121.02 (18) |
C14—N14—C18 | 120.61 (18) | C24—N24—C29A | 120.62 (17) |
C19—N14—C18 | 118.20 (18) | C28—N24—C29A | 117.52 (18) |
N14—C18—H18A | 109.5 | N24—C28—H28A | 109.5 |
N14—C18—H18B | 109.5 | N24—C28—H28B | 109.5 |
H18A—C18—H18B | 109.5 | H28A—C28—H28B | 109.5 |
N14—C18—H18C | 109.5 | N24—C28—H28C | 109.5 |
H18A—C18—H18C | 109.5 | H28A—C28—H28C | 109.5 |
H18B—C18—H18C | 109.5 | H28B—C28—H28C | 109.5 |
N14—C19—H19A | 109.5 | N24—C29A—H29A | 109.5 |
N14—C19—H19B | 109.5 | N24—C29A—H29B | 109.5 |
H19A—C19—H19B | 109.5 | H29A—C29A—H29B | 109.5 |
N14—C19—H19C | 109.5 | N24—C29A—H29C | 109.5 |
H19A—C19—H19C | 109.5 | H29A—C29A—H29C | 109.5 |
H19B—C19—H19C | 109.5 | H29B—C29A—H29C | 109.5 |
C16—C15—C14 | 120.73 (19) | C26—C25—C24 | 121.17 (19) |
C16—C15—H15 | 119.6 | C26—C25—H25A | 119.4 |
C14—C15—H15 | 119.6 | C24—C25—H25A | 119.4 |
C15—C16—C11 | 121.34 (19) | C25—C26—C21 | 121.44 (19) |
C15—C16—H16 | 119.3 | C25—C26—H26A | 119.3 |
C11—C16—H16 | 119.3 | C21—C26—H26A | 119.3 |
O18—C17—O17 | 122.4 (2) | O28—C27—O27 | 121.7 (2) |
O18—C17—C11 | 118.54 (19) | O28—C27—C21 | 118.98 (19) |
O17—C17—C11 | 119.06 (19) | O27—C27—C21 | 119.33 (19) |
C17—O17—H17 | 109 (3) | C27—O27—H27 | 115 (3) |
C17—O18—H18 | 118 (4) | C27—O28—H28 | 120 (4) |
| | | |
C16—C11—C12—C13 | 0.6 (3) | C26—C21—C22—C23 | −0.3 (3) |
C17—C11—C12—C13 | −176.99 (18) | C27—C21—C22—C23 | 177.40 (18) |
C11—C12—C13—C14 | 0.0 (3) | C21—C22—C23—C24 | −0.4 (3) |
C12—C13—C14—N14 | 179.80 (18) | C22—C23—C24—N24 | −179.02 (19) |
C12—C13—C14—C15 | −0.8 (3) | C22—C23—C24—C25 | 1.2 (3) |
C15—C14—N14—C19 | 177.86 (17) | C25—C24—N24—C28 | −172.88 (19) |
C13—C14—N14—C19 | −2.8 (3) | C23—C24—N24—C28 | 7.4 (3) |
C15—C14—N14—C18 | 5.1 (3) | C25—C24—N24—C29A | −3.7 (3) |
C13—C14—N14—C18 | −175.61 (18) | C23—C24—N24—C29A | 176.62 (18) |
N14—C14—C15—C16 | −179.58 (18) | N24—C24—C25—C26 | 178.78 (18) |
C13—C14—C15—C16 | 1.1 (3) | C23—C24—C25—C26 | −1.5 (3) |
C14—C15—C16—C11 | −0.5 (3) | C24—C25—C26—C21 | 0.9 (3) |
C12—C11—C16—C15 | −0.4 (3) | C22—C21—C26—C25 | 0.1 (3) |
C17—C11—C16—C15 | 177.22 (18) | C27—C21—C26—C25 | −177.66 (18) |
C16—C11—C17—O18 | 1.8 (3) | C22—C21—C27—O28 | −176.16 (18) |
C12—C11—C17—O18 | 179.34 (18) | C26—C21—C27—O28 | 1.5 (3) |
C16—C11—C17—O17 | −177.27 (18) | C22—C21—C27—O27 | 3.0 (3) |
C12—C11—C17—O17 | 0.2 (3) | C26—C21—C27—O27 | −179.34 (17) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O17—H17···O18i | 0.93 (6) | 1.70 (7) | 2.607 (2) | 164 (4) |
O18—H18···O17i | 0.83 (9) | 1.80 (9) | 2.607 (2) | 166 (7) |
O27—H27···O28ii | 0.89 (7) | 1.71 (7) | 2.603 (2) | 173 (5) |
O28—H28···O27ii | 0.84 (9) | 1.77 (9) | 2.603 (2) | 175 (6) |
Symmetry codes: (i) −x+1, −y, −z+2; (ii) −x+2, −y, −z+2. |
Experimental details
| (II) | (III) |
Crystal data |
Chemical formula | C9H11NO2 | C9H11NO2 |
Mr | 165.19 | 165.19 |
Crystal system, space group | Monoclinic, P21 | Triclinic, P1 |
Temperature (K) | 173 | 173 |
a, b, c (Å) | 10.3202 (10), 7.4068 (8), 11.2845 (11) | 9.6507 (11), 9.8918 (11), 10.0082 (10) |
α, β, γ (°) | 90, 105.505 (5), 90 | 76.118 (6), 67.655 (7), 69.334 (9) |
V (Å3) | 831.19 (15) | 820.61 (15) |
Z | 4 | 4 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.09 | 0.10 |
Crystal size (mm) | 0.35 × 0.30 × 0.10 | 0.30 × 0.20 × 0.10 |
|
Data collection |
Diffractometer | Bruker SMART CCD area-detector diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | – | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5542, 1982, 1280 | 5655, 3506, 1717 |
Rint | 0.054 | 0.059 |
(sin θ/λ)max (Å−1) | 0.661 | 0.649 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.047, 0.132, 0.96 | 0.052, 0.142, 0.85 |
No. of reflections | 1982 | 3506 |
No. of parameters | 223 | 235 |
No. of restraints | 1 | 0 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.20, −0.23 | 0.21, −0.28 |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
O17—H17···O28i | 0.87 (4) | 1.74 (4) | 2.609 (3) | 174 (4) |
O27—H27···O18ii | 0.83 (4) | 1.78 (4) | 2.602 (3) | 175 (4) |
Symmetry codes: (i) x−1, y, z−1; (ii) x+1, y, z+1. |
Hydrogen-bond geometry (Å, º) for (III) top
D—H···A | D—H | H···A | D···A | D—H···A |
O17—H17···O18i | 0.93 (6) | 1.70 (7) | 2.607 (2) | 164 (4) |
O18—H18···O17i | 0.83 (9) | 1.80 (9) | 2.607 (2) | 166 (7) |
O27—H27···O28ii | 0.89 (7) | 1.71 (7) | 2.603 (2) | 173 (5) |
O28—H28···O27ii | 0.84 (9) | 1.77 (9) | 2.603 (2) | 175 (6) |
Symmetry codes: (i) −x+1, −y, −z+2; (ii) −x+2, −y, −z+2. |
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It has previously been demonstrated that 4-N,N-dimethylaminobenzoic acid, (1), is capable of forming binary (Sharma et al., 1992, 1993) and ternary (Aakeröy et al., 2001) cocrystals as a result of its propensity for engaging in heteromeric complementary hydrogen-bond interactions with carboxylic acids or carboxamides (Aakeröy et al., 2004), as well as with N-heterocyclic compounds, coupled with a capacity to act as a donor moiety in π-π* charge-transfer donor complexes. With this information in mind, (1) has been used extensively in our laboratory as a cocrystallizing agent, especially since it has also been shown that heterodimers in acid–acid cocrystals, (Hanton et al., 1992; Etter, 1990) gain increased stability as a result of the variation in hydrogen-bond donating/accepting ability of the two different carboxylic acid moieties (Etter & Frankenbach, 1989).
During the course of systematic cocrystallization experiments involving a variety of carboxylic acids [including (1)] and ditopic N-heterocyclic compounds, we obtained two new polymorphs of 4-N,N-dimethylaminobenzoic acid. Views of the molecules in forms (II) and (III), with the atom-numbering schemes, are presented in Fig. 1. Form (I) was previously obtained from water–alcohol mixtures (Vyas et al., 1978) and acetone (Anulewicz et al., 1987).
In (II), near-linear O—H···O hydrogen bonds between adjacent, crystallographically inequivalent carboxylic acid moieties generate the dominating intermolecular interactions and result in well known dimeric acid–acid motifs [O27—H27···O18ii, O···O = 2.602 (3) Å, and O17—H17···O28i, O···O = 2.609 (3) Å; symmetry codes as in Table 1). Adjacent dimers are positioned with their methyl-substituents `back-to-back', resulting in linear one-dimensional arrangements of dimeric units (Fig. 2).
Form (III) also contains two crystallographically inequivalent molecules; however, symmetry-related molecules form dimers resulting in two distinct chains. The relevant intermolecular O—H···O interactions for the two forms are O17—H17···O18i [O···O = 2.603 (2) Å] and O27—H27···O28ii [O···O = 2.600 (2) Å]. (The H atoms in each of these two interactions are actually disordered between the two O-atom sites, so that each O atom acts as a donor and an acceptor with roughly equal populations.) Adjacent dimers organize themselves in the same way as the dimers in forms (I) and (II), with relatively short contacts between methyl groups on adjacent dimers within each chain (Fig. 3).
The amine substituent in all three forms is approximately coplanar with the ring to which it is attached (all relevant torsion angles are less than 5°). It has previously been postulated that polymorphic compounds make good cocrystallizing agents (Aakeröy et al., 2003). This statement is supported by, for example, 3,5-dinitrobenzoic acid, a compound that displays several polymorphic forms (Prince et al., 1991; Kanters et al., 1991; Domenicano et al., 1990) and is known to be an excellent cocrystallizing agent (Pedireddi et al., 1998; Bott et al., 2000; Grabowski et al., 2001). In light of the new polymorphs of (1), 4-N,N-dimethylaminobenzoic acid lends further support to the notion that good cocrystallizing agents with appropriate hydrogen-bonding substituents are quite likely to be found amongst polymorphic compounds.